trolling motor battery issues, 1997 Pantera II

We are the proud new owners of a Bass Cat boat. First boat bought for me and my son. I grew up with my Dads small aluminum boat and little DuckTwin engine, so this is a big leap for us. Learning a lot.The trolling motor has been running out of juice part-way through a day on the water. Took the batteries that were in the boat when bought to get tested and the first one tested was charged but low on capacity so we replaced them. Same thing started happening after a day or two with the new batteries. Finally started monitoring the battery charges (the battery indicator up front for the trolling motor lights up but doesnt show any voltages, for some reason, maybe related to this problem).On the water yesterday I took a reading after the trolling motor grew weak. The forward most of the two trolling batteries was down around 4 something, I think. Maybe the sun glare made me get that wrong. Yikes. The other was 12.22 or so. I took the reading again when we pulled in after running back to the ramp. Both were stronger, the one was up to 9 (maybe the 4 I read earlier was a 9?) and the other was up to 12.5 or so.Got home and charged them overnight (ProMariner ProSport Plus 3-bank charger). The weak battery now reads 11.47 and the other 13.07. (I did take readings on the batteries when new and they both read 12 something from the store, and I took some readings after running and charging and noticed a difference which has now gotten worse.)It seems as if trolling motor is only getting power from the one battery. Pulled the batteries out with the wires attached, hoping to see if they are wired properly and learned that there are essentially two sets of identical wires running from each and these go down around the gas tank and disappear from sight. A thick black wire comes off of each battery, a thin black wire comes off of each, and thick red wire comes off of the rear-most battery, a thick white wire comes off of the front-most battery, a thin red wire comes off of each. (and the charger wires come off of each.) From what I have read so far on the boards, Bass Cat runs both sets of wires up to the front and then the trolling motor plug has the jump done in the plug itself.)So, I am not sure what to do next.- Is the one battery now permanently injured after the deep discharging? Or is there maybe also a problem with one bank of the charger? How to diagnose?- There are circuit breakers on wires coming off of the positive terminals. The thick wires have 50amp breakers. I cant tell what size the thin red wires have on them.? We replaced one with a 20amp breaker that the marine shop decided on, not sure how. Is that the right size? (I noticed a lot of rust around one and it broke when trying to remove and clean. I see something similar on the crank battery. Should I replace that also? What size is that breaker?)- What are the thin red and black wires for? I assume the thick ones are for the trolling motor. Are the thin ones for the battery gauge?- I thought only the cranking battery recharged when the (200 hp Mercury EFI) is running. But, it seemed as if maybe the trolling batteries were recharging from the running also. Is that likely?- How to diagnose further what might be causing the trolling motor to draw down only the one battery?Thanks in advance for any and all help.- Steve

This topic has 9 replies, 3 voices, and was last updated 13 years ago by ctford.

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May 12, 2012 at 2:36 pm #456986

Bass Cat Boats
Keymaster

sounds like you are running on one battery, my 88 could run on 12 and 24 there is a switch on front panel to change between the 2 switch could be bad or behind that is. a terminal block where both sets of cables come on, check that also for good connection. what model trolling motor?pete

May 12, 2012 at 6:30 pm #456987

Bass Cat Boats
Keymaster

Sine your boat is a 1997 with multiple owners it is hard to say what you are up against without seeing the rig. It sounds like the batteries are charging, though one still needs more. You are going to either have to learn the system or seek help.

May 12, 2012 at 9:30 pm #456988

sdub
Participant

Thanks very much for the responses so far.The trolling motor is a MotorGuide 71lbs thrust, 24v motor. The system has had two owners as far as I can tell. One the original pro and the other a guy who didnt use it that much and seemed to take good care of it, using professional mechanics when work had to be done. It looks very much like the setup I have seen described elsewhere, so I dont think its been messed with much.I dont see a switch to go between 12v and 24v. There is a switch that has three positions one for battery 1 and one for battery 2 and then in between. It springs back to the neutral position and when pressed in either direction the battery gauge lights up but for some reason the needle doesnt move for either battery to show the voltage.I took the cover off the plug and put the meter on the black and red terminals and it read 24.7 (the two batteries test directly at 13.05 and 11.68). So it seems as though 24 volts is being supplied to the motor. so why would the one battery draw down and not the other?Not sure what is meant by “learn the system” other than what I have been doing in trying to figure out how it is wired and isolate the issues. I did send an email today to BassCat service for help also.- steveLast edited by sdub on May 12th, 2012, 9:35 pm, edited 2 times in total.

May 12, 2012 at 9:46 pm #456989

Bass Cat Boats
Keymaster

Is it possible that your trolling motor plug is wired for 12 volt and not for 24? Check you voltage at the plug where you motor plugs in. This is just a thought.georgeGeorge

May 12, 2012 at 10:04 pm #456990

Bass Cat Boats
Keymaster

It requires four wires to the front panel so slip that panel out and make sure there are four wires on the back side. Then make sure which goes to which pin. The plug you show depends on how the panel receptacle is wired as to whether you have 12 or 24 volts. If you have four large wires on the batteries, then you only have 12 volts on the troller. That metal strap you see between the two open pins holes (screw terminals) makes the 24 volts or 36. There will be three wires on each battery, one set for 6 gauge leads, one set for that gauge you show (to switch mentioned), and one set for a charger (if onboard). The batteries work like a flashlight. Two 1 1/2 volt batteries in a flashlight makes it a 3 volt light. The negative and positive batteries stack and connect the two batteries. Your 12 volt batteries work similar. Try connecting the wires to the troller differently on the actual plug shown open and on the 24 or marked 36 volts if newer. Older ones were marked as 12 & 24 for red wires. We do think you only have 12 volts in use and that would burn a battery hard. Be absolutely sure you have circuit breakers inline to protect from shorting or fire.

May 12, 2012 at 11:07 pm #456991

Bass Cat Boats
Keymaster

Here are photos of the two batteries with the three wires coming off of each terminal (trolling motor, battery gauge, charger). You can see the circuit breakers on the positive wires for the trolling motor and the gauge.

May 12, 2012 at 11:11 pm #456992

Bass Cat Boats
Keymaster

Looks good from here. Check the plug terminals with a voltmeter for voltage and connect the red trolling motor wire to the one that says 24 volts. On second thought, it may be properly connected to the right terminal up front so check voltage.

May 12, 2012 at 11:24 pm #456993

sdub
Participant

The trolling wires coming off of each battery are connected to the plug, as seen in the attached photos. The wires still have their original numbering on them as well. I think it was the number 1 battery that is the one being drawn down when the motor runs, as if it was the only battery being used. Its wires connect to the vertical prongs on the plug. Battery 2s wires connect to the horizontal prongs. The voltages read the same up front for each battery as they do directly off the battery terminals. And, as noted above, the two wires for the trolling motor read 24 volts at their posts on the plug. Seems to me the wiring is as expected and working. No? Still a mystery to me why battery 1 drains a lot with trolling, but not battery 2. Maybe battery 1 is just bad, even though new? It drains quicker and then even though battery 2 still has 12.+ volts, together they are no longer enough to power the trolling motor strongly.

May 12, 2012 at 11:28 pm #456994

ctford
Participant

Not sure it will be on much help but my 1998 Sabre has a foot petal that looks like the one in the picture and has a 12/24 volt switch on the side. I use it all the time. Batteries are wired both parallel and in series so I can have twice the power or twice the run time.
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